File systems for optical discs have made advances through various activities to develop UDF (Universal Disk Format®) specifications published from OSTA (Optical Storage Technology Association).
For write-once discs, the recording method has improved from multi-session recording to file-by-file recording using VAT (Virtual Allocation Table).
On the other hand, for rewritable discs, a volume and file structure has improved from the structure using non-sequential recording defined in ECMA 167, which is the international standard, to the structure using Metadata Partition specified in UDF Revision 2.5 (hereinafter UDF 2.5). The merits to use Metadata Partition are the improvement in the performance to retrieve metadata, such as file entries/directories, and to increase the robustness from media damage.
However, Metadata Partition cannot be used for data appending usage on a write-once disc. This is because it is not allowed in UDF 2.5 to use Metadata Partition with VAT, due to the difficulty to implement this combination.
Typically, it is also difficult to develop a new recording method for a write-once disc. This comes from the physical characteristics such as that the data written at once cannot be overwritten, hence it would be required to study from the several aspects, to be consistent with computer architecture, the possibility of implementation for drive apparatus, the restrictions due to the dedicated resource of consumer appliances, etc.
The present invention has been made in view of the above subjects and includes an objective of providing the merits of Metadata Partition to the data recording usage on a write-once disc.